The present invention relates to minute dose hypodermic syringes, and relates more particularly to a safety minute dose hypodermic syringe which permits the needle cannula to be pulled back inside the barrel after the injection, and then deformed by the plunger by removing the plunger out of the rear end of the barrel and then inserting it into the front end of the barrel.
In order to prevent contamination, regular hypodermic syringes are commonly made disposable. FIG. 1 shows a regular minute dose hypodermis syringe which is generally comprised of a barrel, a locking tip fixedly secured to the front end of the barrel on the outside to hold a needle cannula, and a plunger having a front end coupled with a rubber stopper moved in the barrel. The needle cannula must be damaged by a syringe crusher or the like after the injection, to prevent possible contamination. FIG. 2 shows a safety minute dose hypodermic syringe according to the prior art in which the locking tip is coupled to the front end of the plunger. After the injection, the plunger is pulled backwards to move the needle cannula to the inside of the barrel, and then the front end of the plunger is broken and retained on the inside of the barrel. However, because the needle cannula is still maintained intact, it may injure someone when the barrel is broken.